Electric-arc lamp



J. A. HEANY.

ELECTRIC ARC LAMP.

APPLICATION FILED JUNE 11. 1917.

1,403,07 Patented Jan.10, 1922.

UNITED. STATES PATENT OFFICE.

JOHN ALLEN HEANY, OF NEW YORK, N. Y.

ELECTRIC-ARC LAMP.

To all whom it may concern:

Be it known that I, JOHN ALLEN HEANY, a citizen of the United States,residing in the city, county, and State of New York, have inventedcertain new and useful Improvements in Electric-Arc Lamps; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

The invention relates to electric arc lamps operating on very lowwattages and at ordinary commercial voltages and maintaining highefliciencies even in the smaller sizes ranging as low as ten or fifteencandle power. To this end, the invention comprises a lamp, involving acontainer or envelope, preferably adapted for connection in the ordlnaryincandescent lamp socket, and conta ning an inert gas, preferably underdlmmished pressure, and two electrodes between which the arc ismaintained, connected to suitable lead wires or conductors, at least oneof which electrodes is formed of a conductor of the second class, whichis nonconducting when cold, but becomes conductive when highly heated,one or both of said electrodes being associated with a coil or helix ofhighly refractory, metallic wire, spaced from the electrodes, whichserves to heat the electrodes and which constitutes a shunt or by-passaround the electrodes, which is adapted to be broken by suitable means,such as a thermostat, when the arc has been established.

In the accompanying drawings,

Fig. 1 illustrates a lamp involving the invention.

Figure 1 is an enlarged fragmentary View illustrating a modified form ofthe invention.

Figs. 2, 3, 4 and 5 are fragmentary views illustrating modifications ofthe construction and arrangement of the electrodes and the heatingelement.

vReferring to the drawings, 1 indicates a bulb or container of the typeusually employed in incandescent filament lamps, adapted for the usualsocket connection, which is exhausted of air and supplied with an inertgas, such as nitrogen, argon, or the like, preferably under diminishedpressure. The bulb is provided with the usual form of glass neck 1'containing the supply leads and to which is attached a supporting wire 5to element 4, which become Specification of Letters Patent. Patented J1922 Application filed June 11, I

1917. Serial No. 174,102.

which is connected a lead wire 2 containing a ballast resistance 4 inthe form of a coil of highly refractory metallic wire, such as tungsten,mounted upon a rod-like support 3 of refractory oxide, which wire andsupport become incandescent uponthe passage of current. To the lower endof the support 5 is attached by means of a clamp 5 a rodlike electrode10, which is surrounded by a helix of highly refractory metallic wire,such as tungsten, spaced from the electrode and connected to theconducting support 5 at one end. Said electrode 10 consists of aconductor of the second class, which is nonconducting when cold, butbecomes conductive and are supporting when highly heated, and mayconsist of a mixture of highly refractory oxides, such as oxide ofzirconium, oxide of thorium and oxide of yttrium. The opposite electrode11 may be made of the same form and materials as electrode 10, but, onthe other hand, it may comprise a suitably formed body of highlyrefractory metal, such as tungsten or tungsten alloy, and is supportedfrom a thermostat 12 by means of a clamp 12 carried by a stiff wire l2fused to the thermostat which is in turn anchored at one end in the neck1 and connected to the other lamp terminal by means of a conductor 14.When the electrode 11 corresponds to the opposite elec- L trode 10, itis surrounded by a continuation of the heating and resistance coil 6,which latter terminates in a contact 7 carried by a support 8 anchoredat its upper end in the neck 1', which contact normally engages a fixedcontact 13 carried by the thermostat.

It will be understood that when the electends to strike across the arc,and acts as an ionizer of the gas surroundingthe electrodes to initiatethe starting of the arc.

The operation of the lamp is as follows: Current enters by way of lead2, passes through the ballast resistance and heating incandescent,thence by way of support 5 to helix 6 surroundin the electrodes 10 and11, thence to contact and contact 13 to thermostat 12 and by way ofconductor 14 back to the other terminal of the. lamp. The highlyrefractory metallic helix 6 immediately incandesces and imparts its heatto the electrodes 10 and 11 and also to the surrounding gas to ionizethe latter, thereby establishing the are between the ends of theelectrodes 10 and 11. The heat generated acts upon thermostat 12 andcauses the same to move electrode 11 away from the electrode 10 toproper arcing distance, and at the same time, breaks the circuit of theby-pass or shunt formed by the heating coil 6, at contacts 7 and 13, sothat all of the current passes through the arc, which is maintainedbetween the ends of the electrodes. The thermostat is provided so as tobreak the shunt and allow all the current to pass across the arc andalso to bring the electrodes to the proper position to obtain the mostefficiency. While the electrodes are shown spaced, yet the spacing atthe time of starting the lamp is less than during the operation thereofso as to allow for quicker starting of the arc. Inasmuch as theelectrodes are second-class conductors, the device is operative equallywell with the electrodes in contact at the time of starting.

In the modification shown in Fig. 2, the electrodes 10 and 11 areprovided with bulbous heads or terminals 10 and 11 and the heatingelement 6 is disposed above the terminals. The electrodes are heateduntil they become conductive and the arc strikes. The shunt is thenbroken and the current all passes through electrodes:- These electrodesare so proportioned that their resistance is sufficient to act as aballast for the are.

In Fig. 3, the ballast is incorporated directly in the leads 2 and 14,and preferably consists of coils or filaments 4, 4" ofhighly refractorymetal, such as tungsten, which not only serves as heaters, but also asincandescent lighting elements per se. In this arrangement, theelectrodes and the heating coils 6 are arranged in a similar manner asillustrated in Fig. 1, and the thermostat 12' is interposed between theballast 4" and the electrode 11.

In Fig. 4, the arrangement is similar to that illustrated in Fig. 3,except the heating coil 6 is arranged above the electrodes, as in Fig.2.

In Fig. 5, the construction and arrangement is similar to thatillustrated in Fig. 2, except for the fact that the neck 1' is extendedin the form of a stem 1" to enable the supporting elements for theelectrodes to be made shorter, and the operating devices of the lampmore compact.

Lamps constructed in accordance with the principles aforesaid develop asteady, brilliant are between the electrodes, emitting light of aquality and {character ICIOSQIY approximating that of sunlight andoperate under an efliciency of a fraction of a watt per candle power. Inthe particular form of the invention in which the ballast is included inthe circuit of the arc, within the lamp, the said ballast by virtue ofits incandescence augments the light emitted by the are so thatpractically all of the current is utilized for illumination.

lVhat I claim is 1. An arc lamp comprising a container, spacedelectrodes therein, at least one of which is formed of a second classconductor, a heating element of highly refractory metal adjacent to butspaced from said second class conductor electrode and normally in closedcircuit between the supply leads to the lamp and serving to heat theelectrode to conductivity, and means to maintain said electrodes atproper arcing distance, said means being effective to break the circuitthrough the heating element, when the arc has been established betweensaid electrodes.

An arc lamp comprising a container. spaced electrodes therein, at leastone of which is formed of a conductor of the second class, supply leadsconnected to said electrodes, a heating coil of highly refractory wireadjacent to but spaced from said electrode and normally in closedcircuit be tween the supply leads to heat the electrode to conductivity,and a thermostat adapted to maintain the electrodes at proper arcingdistance, said thermostat being effective to break the circuit throughthe heating coil when the arc has been established between saidelectrodes.

3. An arc lamp comprising a container, spaced electrodes therein, atleast one of which is formed of a second class conductor, circuitconnections for said electrodes, one of which connections includes athermostat adapted to maintain the electrodes at proper arcing distance,and a heating coil in parallel with and adjacent to but spaced from saidelectrodes to heat the latter to conductivity, and contacts carried bysaid coil and thermostat adapted to beseparated by movement of thethermostat to break the circuit through the heating coil when the archas been established between the electrodes.

4. An arc lamp comprising a container, spaced electrodes therein, atleast one of which is formed of a second-class conductor, circuitconnections for said electrodes including a thermostat adapted toregulate the distance between said electrodes, a heatin element adjacentto but spaced from said second-class electrode, one end of said heatingelement being connected to one lead wire and the other end to an anchorcarried by the container, contacts on said heating element andthermostat to clos the circuit through said heating element when theelectrodes are in their closest relation.

5. An arc lamp comprising a container, a lead wire in said container,spaced elec- .trodes in said container, at least one of which is formedof a second-class conductor, circuit connections for said electrodesincluding a thermostat adapted to regulate the distance'between saidelectrodes, a heat ing coil of highly-refractory Wire adjacent to' butspaced from said electrode, said coil being in permanent connection withsaid lead Wire, cooperating contacts on said coil and thermostat wherebysaid coil is normally in closed circuit With said lead Wire andthermostat, and means to support the free end of said coil.

In testimony whereof I aflix my signature.

JOHN-ALLEN HEANY.

